Composition of manganese and iron for brake-shoes



UNITED STATES PATENT ()FFICE.

WILLIAM WV. SNOW, OF I'IILBURN, NEW YORK.

COMPOSITION OF MANGANESE AND IRON FOR BRAKE-SHOES.

SPECIFICATION forming part of Letters Patent No. 435,050, dated August 26, 1890.

Application filed July 9,1889. Serial No. 316,984. (No specimens-l To all whom it 11mg concern.-

Be itknown that I, WILLIAM W. SNOW, a citizen of the United States, residing at Hilburn, Rockland county, New York, have invented certain new and useful Improvements in Brake-Shoes, of which the following is a specification.

A serious objection to ordinary car-brake shoes as made of common cast-iron is their rapid wear and deterioration, necessitating the making of such shoes heavy and cumbersome in the firstinstan ce, thefrequentremoval and replacing of shoes, and the discarding of the shoes before they are nearly'worn out. Many efforts have been made to overcome these defects by altering the construction of the shoes, making shoes of compound parts, some of the parts of hard material, &c., generally with a considerable increasein the cost of the shoe and complexity of construction.

In the course of many efforts to produce'an effective but comparatively inexpensive substitute for the ordinary cast-iron shoes it 00- curred tome to use a metal or alloy of greater hardness than thatheretofore employed, and I began a series of tests and experiments which resulted finally in the discovery that by the addition to ordinary pig metal of a certain proportion of manganese I was able to produce a very soft metal, but that a comparatively slight increase of the percentage of manganese resulted in the production of an extremely-hard metal peculiarly adapted for the purposes for which I intended it. Thus, while an addition of about three to five per cent. of manganese produces a soft and cluetile metal, an increase of the manganese to from eight to ten per cent. greatly hardens the product, imparts great toughness and durability under friction and abrasion, and a brake-shoe made therefrom, while it can be cast in the ordinary manner and at practically no increase in the expense of production, is so much more effective than one of ordinary cast-iron that it may be made comparatively light in weight, used so long as sufficient metal remains to preserve its shape, and the usual expense of constant removals and changes is avoided. The most effective characteristic of the shoe thus made, however, is its durability, resulting from a peculiar combination of toughness and hardness, which enables it to Withstand the friction and abrasion to which it is subjected much better than any material with which I am familiar.

The percentage of manganese Will depend to a great extent upon the character of the pig metal, the proportion of manganese being increased or diminished, according to the proportion of carbon existing in the pig. In some cases it may be necessary to use as high as fifteen per cent. The ingredients may be placed in the cupola, hot-air furnace or crucible, or the manganese may be added as a powder to and mixed with the iron after it has been melted, or the powdered manganese may be thrown into the metal in a converter by means of the blast from the tuyeres.

In my practice Ihave generally introduced the manganese as a powder into the molten metal and mixed it thoroughly therewith before pouring into the molds, the manganese being in the form of ferro-manganese and the quantity added being proportioned to give the desired percentage of manganese in the product.

I do not limit myself to any special mode of combining the ingredients of the mixture; but

I claim as my invention A brake-shoe of cast metal made from a mixture of iron and manganese,in which the proportion of manganese is from live to fifteen per cent. of the amount of iron, substantially as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM IV. SNOlV.

Witnesses:

A. A. FINoH, PETER D. J OI-INSON. 

